This invention relates to a terminal-cover assembly for a multisection round capacitor, and more particularly to such an assembly that exceeds the minimum spacing requirements for terminal-terminal distance and terminal-rim distance. The invention also relates to a four-bladed terminal for the assembly that meets the spacing requirements even for small capacitor sizes.
Multisection capacitors are often used for AC motor-start and motor-run service. Frequently, they have a common electrode, thus requiring only three terminals. When three terminal units are housed in oval containers, the terminals can be mounted in the cover in a line and still meet customer and Underwriters Laboratory (UL) requirements for terminal spacing.
The UL spacing requirements are that there must be at least 0.125 inch (3.18 mm) between terminals and between terminals and the rim of the can or housing for 0-300 V service. When terminals are of opposite polarity, then the above spacing must be 0.25 inch (6.35 mm). For 301-600 V service, this minimum spacing becomes 0.375 inch (9.525 mm).
When three terminal capacitor units are housed in round containers, which provide greater volumetric efficiency, the terminals cannot be mounted in a line and still meet the foregoing minimum spacing requirements. Generally three terminals are mounted in the cover of round containers in a triangular array. For cover sizes of three inch diameter or less using standard terminals in standard bushings, there is even a problem in using multiple blade terminals and still meeting the minimum requirements for distance between terminals and distance between terminals and edge of the housing.